Controller for electric motors and similar devices.



H. W. LEONARD.

CONTROLLER FOR ELECTRIC mo'rons AND SIMILAR DEVICES. APPLICATION TILED JULY 15,1912.

1,077,615, Patented Nov. 4, 1913.

UNITED STATES PATENT OFFICE.

HARRY WARD LEONARD, OF BBONXVILLE, NEW YORK.

CONTROLLER FOR ELECTRIC MOTORS AND SIMILAR DEVICES.

Specification of Letters Patent.

Original application filed July 11 1903, Serial No. 165,681. Divided and application filed May 17, 19-33,

Serial No. 374,180. Divided and this application filed July 15, 1Q 12-.

Serial No. 709,4;31 2.

To all whom it may concern:

Be it known that I, HARRY \VARI) LEONARD, a citizen of the United States, residing at Bronxville, in the county of Westchcster and State of New York, have invented certain nevv and useful Improvements in Coir trollers for- Electric Motors and Similar Devices, of which the following is a full, clear, and exact specification.

This application is a division of my pendmg application for improvement in controllei-s for electric motors, and similar devices, filed May 17, 1907, Serial Number 374,130, renewed July 18, 1910, Serial Number 572,581, being a division of my original application, filed July 11, 1903, Serial-Number 165,061, on which Letters Patent Number 855,897, was granted June 4, 1907.

My invention relates principallyto the devices employed for starting and regulating the. speed of electric motors, and to the devices employed for protecting such devices and the motor against damage due to ubnormal variations in the circuit. llcretofore such devices, and particularly the starters and field controllers, were prefer ably entirely separate pieces of apparatus and were operated independently of each other. nut-l1 arrangement ot' the controlling; devices are frequently the cause of injury to the motor and controlling means due to the improper o 'ieration of the separate dcviccs and to carelessness or ignorance on the part of the dpcrator. a

One object of my invention is to combine a ,motor starter, speed regulator and automatic protective devices with means, where by the several elements constituting a controllcr (an only be operated in the proper sequence to start and regulate a motor, and so that the protective devices will always be in a position to respond to abnorn'nii changes in the motor circuitrand whereby the starting of a motor and the control of its speed will be fool proof that is to say, the con trolling apparatus and the motor will be entirely safe. even in the hands of inexpericnccd, careless or ignorant operators.

in the operation of many kinds of machine tools and other appliances by electric motors, it is very desirable that there be provided a simple. ctlicient, reliable, inexpensive and coin 'mct form of controlling apparatus by moans of which the motor can be started and brought to full speed, and later, if necessary, operated at any speed over Wide a range of speed as possible. On account of the etliciency and simplicity of the method, it is very desirable to secure the speed variation by varying the field strength of the motor. Electric motors have now been so far improved as regards freedom from sparking, that they require. very little attention in operation. even when the field is varied over a very wide range, and hence in the future these motorswill be vcry ex tensively employed in the operation 0 mm chine tools and in performing many other kinds of work where a Wide range of speed is of value, and especially Where the torque varies inversely as the speed to such an extent that the power of the motor is more or less constant. The controlling apparatus for such i'notors should have the following than 'a teristics rst, an overload protect ive device which will positively and with sutlicient promptness open the circuit to the motor it' under any conditions of starting or operation a current greater than a certain predete mincd amountshould flow in the motor circuit. t er-mid. this overload device must be such that the motor can be safely and simply started up again by the operator without loss oi time and without. expense. Third, a no-voltugc release or clcctro-respousive device which will automatically act it the supply voltage fails, or rcdurcd to a very low point, to protect the motor against tho risks due to a sudden rise to full voltage. and such no-voliag device shall be dependent upon the volts upon the motor aruuiturc and shall be iudcpcndent of any current through the motor. Fourth, a dcvice by the nuinipulalion of which the operator can readily change the speed of the 'motor gradually and over a wide range so that. for example, a culling tool can be worked in the most ctlicicnl. nmnncr at any speed and out within the capacity ol the motor. Fifth. a starting rhoostat. Sixth, interlocting or functionally rclzu'ml mochauism. or equivalent arrangement of mochauism. which will insure the proper sequence of adjustments, and whereby it will be i|npossible for the o icrator to start the mo or while the motor lias an improperly weal-a cued field. \Vhilc this interlocking or equivalent mechanism is preferably arranged directly between tho speed controlling device and the motor starter, it is evident that it Pr tented Nov. 4,191 3.

IOlnl oi my invention, and.

may iu- :nppl ml between any device, controlling the speed conlrollcr and any device which controls the cur-rein passing through the motor armature. such as a switch in Series with the motor armature and starter.

lv inn-n h n ilhr-iratcd in tho accomiuinviug drawings, in which" lw'iu-e l :1 diagram illustrating one Fig. is a dine grain of a m dified form of my invention.

In Fig. 1 my invention is snown applied to a rciersing controller and in which the ITTPHlIlQ controller and ii lil rhcoslut are funrt low i rrhatcrl so thorthe r sisiancc of the controller cannot he ut out except when the field is in a coiuiition, The armature and field weanling of the motor is indicated at. ill. in. the. main circuit is a switch comprising the two spring pressed arnas A, l). tlic current passing from one supply terminal through the overload solenoid D. which may ct to release arm l3 and open the circuit, then through arms B and A through'the reversing controller and mo tor armature to the other sup terminal. Current also passes: 5 side, of the line throufil' U in resr'tancc R and retaining magnet lo the other side, and there is likewise a circuitacross the line including the field of the motor, the field rcsislancc c and the field rheostat arm 0 The. movable element of rho reversing controllcr comprises an arm is electrically connected to olic side or the linc and cngaging one or the other of two contact, segments I connected in the. icrni nals of the niolor armature. Tho inovziliie clement also includes an insulated conducting portion in which electrically connects the contact segments 1 with concrntric outer strips in, and lhc contacts m of the controlling resistance. The opcrating shaft of rho controller curries a cam u on which rules ihc co roiler urn: is inrncil from the on position so that the part W-engagrm rho ronlacts at tho right. The (lirrr nt will then pass from Say positive line to right-hand wrgliwiil' in, through lhc annatuxe rcsistancc to part lc, scgincnt Z, motor armature. lei't haiul segment Z, arm 7.: to ncgati line, As the arm rotated lefthondeiily, the :ii'niaturi: liflhlitllitft will he gradually out out and will be all cut out: when it" engages rout m. During this oporatirn, th ro l c has r mained at its ieg'iendently from one l 1 l l l i giving a strong field. Upon further movc merit, of the controller, the rod 0 rides upon an inclined portion of cam 71, causing field resistance to be gradually cut in giving a further increase in the speed of the motor. This condition is illustrated in the figure. if now it, is desired to reverse the motor, the, controller arm will he turned in a righthand direction, which first cuts out the field resistance, then cuts in the armature resistance and then breaks the armature circuit.

lonl nuing the. movement brings the part k in contact with the left-hand contacts and part is in contact with the righthand segment Z. Current; then. passes through the armaturo resistance and armature in the opposite direction giving reversal in rotation. Further movemcnnof the controller arm cuts out the armaturc' resistance While tho field is maintained at full strength and afterward weakens the field as previously explained.

In Fig. 2 l have shown an interlocked or functionally related reversing controller, field rheostat and circuit breaker. The circuit breaker is shown in the form of a pivoted switch B, spring pressed by spring at its pivot so as to tend to move the switch to open the. main circuit at contacts 2 A pivoted latch 01 tends normally to engage the pin (1 when the switch is in the closed position and to hold the same closed. A plunger for tripping the latch is shown as having two iron cores. One is acted upon by the coil E which forms a circuit across the line in series with a resistance R through switch B and contacts y and normally tends lo hold the plunger up and which, upon oc rurrence of no voltago, permits the pliiinger to fall and trip the latch (Z and allows the circuit breaker to be opened by spring; .9. The other core is acted upon by coil 1) in series in the main circuit and which upon the occurrcnro of overload is adaptcd to draw tho plunger down to lrip latch d and open the circuit.

The re\ crsing controller is provided with the c-znu'iact, segments Z, Z. the contact segments m, and the. resisthnce contacts m. The controller arm is providcd with an insulatcd conductor k adapted to engage seg ments Z and the plate Z and also provided with an insulated conductor is adapted to connect the segments Z with the segments m or resistance contacts m. The controller arm in the position shown, which is the'ofl' position, engages an extension B of switch B so as to close'the latter. The plate Z is connected to one supply line and the merits in are connected to the other supply line through switch B and contacts 2 The segments .1 are connected to the armature terminals. The motor field coil is shown lmrcst. pr i 'ifi'i hr prr-m re nil spring a and i connected across the line in series with a all field rcs st 3 1- l v v has lherciorc been cut. out i variahlc resistance 0 and arm 0". The arm c is pressed by aspring 8 temding to return' m. The cam 'n' is attached to shaft '21; which is also the shaft of the controller arm. The shape of com 1; is such thsrtin the oil position of the controller, rod ois in its lowest position and oilfield resistance out of circuit.

When the controller arm IS moved in one direction the structure circuit will be closed through the starting sesisteiwe and when thec'rrcuit is first closed the switch ll will be free to open nutomaticalh upon occurrenceof overload or HO-VOllfigQ since the controller arm will not then engage tin: projection B. As the controller arm is moved, the armature resistance will be gradually cut out and will be entirely cert-out when k makes contact with one of the segments m. Up to this position the shape of com n is such that red 0 remains in its lowest posit-icn,*but upon further movement of the controller arm, the rod 0 will .be raised and re sistance cut in the field circuit. When the controller arm is moved in the opposite direction, a similar action will take place eX- ce t that the current through the motor armature will be reversed. It is therefore apparent that if the circuit breaker opens, it can be closed and the motor started again only by first returning the controller arm to off position and when the arm is returned to oil' position, all field resistance will be cut out.

Although I have shown specific forms of my invention herein, my invention may be embodied in various other forms of construction, and it will be understood that my invention is not limited to the precise forms herein shown and described. My invention is also capable of use with currents of different forms and with various types of motors, such as motors of direct or alternating current type.

' Having thus described my invention, I declare that What I claim as new and desire to secure by Letters Patent, is,-

1. A controlling device for an electric motor comprising an armature controlling movable element, a field resistunce controlling movable element, scidelemenls being independently movable, and a. single operating handle for moving both of said elements and for (nursing resistance to be inserted in the field circuit.

2. A. motor having a field Winding energized imlepeudently of its armature current, :1 circuit controlling movable element for controlling the armature and the field circuit, 1 second circuit controlling movable clonwnt fwr controlling resistance in the field circuit and movable independently of said first named element, and 3. single opersiting device for moving said movable elements and for' causing resistance to be inserted in the field circuit.

3. A shunt wound motor, a movable switch element for making and breaking the armature and field circuits of said motor, a :movable element for gradually and controllably weakening the motor field strength, and a common means for moving said elements and for causing the movement of said second element toweaken the motor field to any desired degree.

4- An electric motor having a shunt field winding, two movable motor controlling elements, one of said elements being the movable element of a motor field rheostat, a common operating member for'said-elements and for accelerating the motor by movement of said last named element, a novoltage winding, and an automatic switch, the said switch controlling the three circuits in which are connected the motor armature, the motor field winding and the novoltage winding. v

5. An electric motor, and controlling apparatus, said controlling apparatus comprising a no-voltage controlling magnet, and a movable member for starting the motor and weakening its field strength and for rendering effective the no-voltage magnet.

6. In a motor controlling apparatus, starting and speed regulating mechanism, a no-voltage controlling magnet, and an operating handle for starting the motor, regulating its speed and for rendering the novoltage magnet eflective.

7. In a manually operable motor control ler, an armature resistance, a field resistance and means comprising a movable circuit controlling element for causing by its manual movement the armature resistance to be gradually cut outand thereafter the field resistunce to be gradually inserted, and no voltage protective means comprising a no voltage winding connected in parallel with the motor windings.

8. An automatic circuit breaker element, a motor armature controlling movable element, a motor field controlling movable element, said three elements being protectively related so as to be operable only in definite sequence during the acceleration of the mo- ?01', and a common operating. means there- 9. The combination of a motor armature, a field winding, an armature resistance, a field resistance, a local circuit connecting the motor armature, armature resislmice, field winding and field resistance in series with each other, means comprising a movable element the movement of which element causes said local circuit to be connected to tlic's'upply line, to then cause the armature resist ance to be cut out, to then-cause the field resistance to be inserted, and protective .miued position for n'loving the set-0nd memn l tuli proiwln & 1,077,615

means comprising a protectively funct iona field resistance, each provided With an ally related no voltage windin independent controlling arm, and means 10. An electric motor, an armature removable With the starting arm and inoper sistance, a field resistance, the motor armaalive until the arm reaches its running poture Winding, said armature resistance, a sition for moving the field arm to vary its field winding of the motor and said field resistance. resistance being adapted to be connected in 17. The combination with an electric a rlosed circuit, a circuit. breaker for conmotor, of means for vary ng and reversing neetiug the said closed circuit with the supthe armature current, means for varying the ply circuit. tvvo movable elements for vary field current, an automatic switch in series 7 int the armature and tield resistances rewith the motor armature, and a single movs'pectivelv, and a single operating device for able element for operating said means and moving said elements ior starting and aefor closing said switch. velela g the motor. 18. An electric motor, resistances for-varyll. The combination wi" a niotor'liaving' the nmature and field currents in the ing an armature and a field winding, of motor,auautoumtic switrh, aim-voltage demanually movable motor otnstrolling meelu vice for eontrolling the automatic (nun)- anism comprising an armature resistance, a meat of said switch, and a movable element field resistance, a single element for causing for etmtrolliug said resistances and for clossaid armature and lield resistances to be ing switch. 9.; ried respectively and successively in definite l9. An. eleetric motor, resistances tor vary sequence, means for connecting the armaing the armature and licld rurrents in the ture in a closed local circuit, and means automotor, an auiorna i switch, an overload dematically responsive to abnormal circuit eonvive for controlling the autmnatie movement ditions for causing the opening of'the entire or? said switrh, and a movable element for motor circuit while l aving the motor arms. controlling said resistances and for closing ture connected to sai riloiosed loeal circuit. ole

1'12. The combination with a motor of re versing and speed e-mtrolling mes eonr i prising a singlemm'able element by tlae movement of which under control of the op I orator the current throu" h/1 in, ma l snafu, s\ i a l l... .l .L if murrohmg rue numnuid. station. and a inovnull-oiling: said reslstan es I r ri'oent for w l twee-sing? sale vow-lit than the etleotive strength of the Y igld whul- 1:30 the motor gradually reduced, and autourniv creature protective no voltage means th i F 1?. A. uontrolliug devise for tfltfiil'h' {KM-- tors compri ing a pair of resistances. 0: provided with ts i'esgmel-ive resistant; var: ing movable member, and means in conneo H v V H tion with one of said members and ino'peral WHHJIHQI. 7 live until the member reaches a Predator- 21 g switch: vitch in series with her to gradually and successively insert an: the motor ari'nzuure r onsive to uo-volt- 11o desired portions of its resistance in circuit. Hi1"; and means whereby the mo ement of 14. A coi'ltrolllng device for Qltil'llt, mo said reversing switvh effects the closure of tors comprising a starting and a field re said automalie snitch. sistance provided with manually movable 52 .\n lertrur motor having a field controlling members. means for rendi' ring winding, a reversing switch, an automatic the field .nember operative onlv after the protective switch in series with the motor starting member has rearhed running posiarmature responsive to overload current, lion. and functionally related automatic pro and means whereby the movement of said tective means. reversing switch effects the closure of said 15. A controlling device for electric mo automatic switch and varies the current in tors comprising a pair of gradually varisaid field winding: for controlling the speed able resistances. each provided with an indeof the motor. pendent controlling memlwnaud means couit. An electric motor, a reversing switch, trolled by one of said members and ui pvraan automatic proteetive S 'll('l) in series with tivo until the member reaches a predetex E the motor arumlurc irsponsivo to Ito-voltage 1 mined position for moving the r'eet'ond memand overload. and means whereby the moveber to gradually and uet'e sively insert any ment of said reversing switch efl'ecis the desired portious of its resi lame in circuit. rlosure of said automatic switch.

16. A controlling device for electric 25. An electric motor, an autoi'natic. motors comprising a starting resistance and switch automatically responsive to no-volt- 330 .ument ti'e osv the current in said enemies age and overload in series with the motor armature, means for varying the resistance of the motor armature circuit and for varying the motor field strength, and an element controlling said means and also efieco ing the closure of said automatic switch.

26. In motor controlling apparatus the combination of three functionally related movable elements, one of said elements being an automatic circuit. breaker, one being a motor armature resistance controlling element and one being a motor field resistance controlling element, and a single means for moving all of said elements in definite quence during the starting of the motor 27. A controlling device for an electric motor comprising starting and speed regulating mechanism, a no-voltage magnet 31 a common operating means arranged to start the motor, regulate its speed, and bring tire einri I an'em under the influence of velour-e magnet in a I nor controlling niechenisnn a motor armature resistance, a motor field resistanoe, means comprising a ingle operat ing handlefor cansin by its movement the armature resistance to be out out and then causing: the field resistance to be out in cirwit, a functionally related automatically movablecircnit controlling element for antornai' liy oriening the entire motor circuit. and In =n3 for insuring the closure of said element only when the controlling mechanism in in a protective position.

isaon'y whereof I ainx my ssgna a: at two Wli, r) LlflUNi-KRLL a no Kimmie, i a. as W.- Goon copies of thin patent may be obtalned for five cents each, by addressing the Washington,

f Sommissioner of E's-tents 

